Segmentation Fault in TH1::Fit() Using "WL" Option in ROOT 6.30.x — Was the Poisson Likelihood Behavior Recently Made Stricter?

ROOT
4

For your reference, two years ago, I received expert advice on this method here:
:link: [ROOT Forum: Weighted Log-Likelihood Estimation for Low-Statistics Binned Histogram]([Weighted log likelihood estimation for low statistics binned histogram - #3 by moneta])

This issue is significant for our analysis because we are using Weighted Log-Likelihood Estimation (WLLE) on time histograms where bin entries are Poisson distributed counts with weighting. The WLLE method helps retain statistical power while accounting for per-bin uncertainties properly. So, I really need your help!

Thank you

Byungchul Yu